Also known as: ACTH(4-7)-PGP, Heptapeptide Semax
Half-life: ~2-3 minutes (very rapid degradation; biological effects last hours due to downstream gene expression changes)
Semax is a synthetic heptapeptide derived from the adrenocorticotropic hormone (ACTH) fragment ACTH(4-10), with a Pro-Gly-Pro tripeptide extension at the C-terminus for enhanced metabolic stability. Developed in Russia, it was designed to retain the neurotrophic and nootropic properties of ACTH while eliminating the hormonal (steroidogenic) activity. The resulting peptide demonstrates potent neuroprotective effects, enhancing cognitive function, memory formation, and attention without affecting cortisol or adrenal steroid levels.
One of the most significant mechanisms of Semax involves the upregulation of brain-derived neurotrophic factor (BDNF) and its receptor TrkB, which are critical for neuronal survival, synaptic plasticity, and long-term memory consolidation. Semax also modulates the expression of nerve growth factor (NGF) and other neurotrophins, contributing to its broad neuroprotective profile. Additionally, it influences the serotonergic and dopaminergic systems, which may underlie its reported anxiolytic and antidepressant properties.
In Russia, Semax has been used clinically for nearly three decades in the treatment of stroke, transient ischemic attacks, cognitive disorders, and optic nerve atrophy. It is typically administered intranasally, which allows rapid absorption and CNS penetration. Despite its extensive clinical history in Russian medicine, Semax has not been evaluated in Western regulatory frameworks, and most of the published research originates from Russian scientific institutions.
Semax was developed in the late 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences, in the same laboratory that later produced Selank. It was created by Professor Nikolai Myasoedov and colleagues by modifying the ACTH(4-10) fragment with a Pro-Gly-Pro C-terminal extension for metabolic stability. Semax was approved in Russia in 1996 as a treatment for stroke, transient ischemic attacks, cognitive disorders, and optic nerve atrophy. It is also approved in Ukraine. The peptide has been used clinically in Russian medicine for nearly three decades, with extensive post-marketing experience. It was listed in the Russian Pharmacopoeia and is manufactured by several Russian pharmaceutical companies.
Semax has an excellent tolerability profile based on nearly 30 years of clinical use in Russia. The most common side effect is mild nasal irritation with intranasal administration. Headaches are uncommon. Anecdotal reports of hair loss at high doses exist but are rare and typically reversible. The peptide does not affect corticosteroid levels despite being derived from ACTH, which was a key design goal. No significant drug interactions have been identified. The peptide is suitable for both acute treatment (stroke recovery) and chronic use (cognitive enhancement), with no reported tolerance or dependence.
Dose Range
200-600 mcg
Frequency
Once or twice daily (intranasal)
Duration
10-20 days per course
Dose Range
600-1200 mcg
Frequency
Two to three times daily (intranasal)
Duration
10-14 days
Dosing information is for educational purposes only. Consult a healthcare professional before using any peptide.
Typical Vial Size
5 mg
Water Type
Bacteriostatic water (BAC water)
Mixing Volume
2 mL
Half-Life
~2-3 minutes (very rapid degradation; biological effects last hours due to downstream gene expression changes)
Molecular Weight
813.9 Da
Store reconstituted vial refrigerated at 2-8°C. Use within 21 days. Primarily administered intranasally. Russian pharmaceutical form is supplied as ready-to-use nasal drops (0.1% or 1% solution).
FDA Status
Not FDA approved for human use. Approved in Russia for stroke recovery, cognitive impairment, and optic nerve disease.
Legal Status
Unregulated research chemical in most countries. Prescription medication in Russia and Ukraine.
USA
Not approvedNot evaluated by FDA
EU
Not approvedNot authorized by EMA
UK
Not approvedNot licensed by MHRA
Australia
Not approvedNot evaluated by TGA
Russia
ApprovedPrescription medication since 1996 for stroke recovery, cognitive impairment, optic nerve disease
Ukraine
ApprovedAvailable as prescription nasal spray
Dolotov OV, Karpenko EA, Inozemtseva LS, Seredenina TS, Levitskaya NG, Rozyczka J, Dubynina EV, Novosadova EV, Andreeva LA, Alfeeva LY, Grivennikov IA, Myasoedov NF
Neurochemical Journal (2006)
Comprehensive analysis of Semax neuroprotective mechanisms including BDNF upregulation and neuronal survival pathways in ischemic models.
View Study →Dergunova LV, Filippenkov IB, Stavchansky VV, Denisova AE, Yuzhakov VV, Mozerov SA, Khvorova IA, Limborska SA, Myasoedov NF
Frontiers in Neuroscience (2020)
Genome-wide transcriptomic study revealing Semax modulation of gene expression patterns involved in neuroprotection, inflammation, and neurotransmitter signaling.
View Study →Dergunova LV, Filippenkov IB, Stavchansky VV, Limborska SA, Myasoedov NF
BMC Genomics (2014)
Demonstrated that Semax modulates immune and vascular gene networks in ischemic brain tissue, providing molecular evidence for its stroke recovery applications.
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